The linear properties of electrical components with multiple ports are generally characterized by one of the characteristics matrices, e.g. the impedance or transmittance matrix. These matrices can be measured using suitable circuitry.
In general, all elements of the characteristics matrices are frequency dependent, and therefore the measurements must be carried out for different frequencies.
It has been found that conventional methods of measurement may provide poor results because limited precision of the measurement devices and electric noise, in particular if different elements or eigenvalues of the characteristics matrices strongly differ in magnitude. In these cases, information may be lost. On the other hand, the interactions between different electrical components or subsystems in a system can only be described precisely if the properties of the characteristics matrices are well known.
The invention relates to the closest state of the art as shown in the article by Si. Fang, “Electrical modeling of main injector dipole magnets”, Fermi National Accelerator Laboratory (Mar. 17, 1995). Fang discloses a device for characterizing the linear properties of a five-port electrical component, which in this case is a dipole magnet. The device has voltage sources and current sensing units for electrical measurement of the admittance matrix elements as a function of frequency.
In the User's Guide by Agilent Technologies, “Agilent 4155C/4156C Semiconductor Parameter Analyzer”, Volume 1, General Information, Agilent Part No. 04156-90010, Edition 1 (January 2001), a device for characterizing the linear properties of an electrical component with several ports is disclosed. The device has dc or pulsed voltage sources, current monitoring units and a remote control unit for automated measurement. The device performs both measurement and analysis of measurement results.
U.S. Pat. No. 4,156,842 A discloses a system for characterizing the linear properties of an electrical network having at least one port. The device uses high-frequency signal generators and voltage and current sensing units for automated measurement.
In the article of P. Guillaume et al., “Parametric Identification of Two-Port Models in the Frequency Domain”, IEEE Instrumentation and Measurement Technology Conference, p.263-271, Vol. Conf. 8, Atlanta (May 14, 1991), a method and device for characterizing linear two-ports is disclosed. The input and output voltages and currents are measured simultaneously in the frequency band of interest. An analysis of the measurement data is presented that takes care of noise and calibration errors in the input-output data.
In the cited state of the art a single measurement procedure is performed and refined analysis methods are disclosed for improved estimation of the linear properties of the electrical system.